Safety and immunogenicity of an

Area of Science:

• Vaccinology
• Immunology
• Microbial Biotechnology

Background:

• A bivalent HPV 16/18 vaccine produced using Escherichia coli (E. coli) has received WHO prequalification.
• This study evaluates a second-generation nonavalent HPV (9vHPV) vaccine manufactured via E. coli expression.

Purpose of the Study:

• To assess the safety and immunogenicity of a novel 9vHPV vaccine.
• To evaluate two different dosage levels (135 μg and 270 μg) of the candidate vaccine.

Main Methods:

• A single-center, open-label, phase 1 dose-escalation clinical trial.
• 24 volunteers aged 18-45 received vaccinations on a 0/1/6-month schedule.
• Adverse events (AEs) and serious adverse events (SAEs) were monitored; serum IgG and neutralizing antibody (nAb) levels were analyzed.

Main Results:

• The incidence of AEs was 66.7% (135 μg) and 83.3% (270 μg); all were mild/moderate, with no SAEs.
• No significant laboratory parameter changes were observed.
• High seroconversion rates for both IgG and nAbs against most HPV types were achieved by month 7.

Conclusions:

• The E. coli-produced 9vHPV vaccine is preliminarily well-tolerated and immunogenic.
• The findings support further clinical development in larger cohorts and diverse age groups.